99 



hollevved out in the middle, where somewhat more than the upper quarter forms 

 a round light purple patch, with greenish blue rather coarser scales in the 

 middle. The secondaries are almost entirely blue, and the base white greenish 

 with light grey inner margin; dark grey tail corner, marked with a little red 

 yellow and greenish blue, towards the wing apex narrow black posterior margin 

 and blackish brown fringes. In the d' the blue field of the primaries is larger, 

 rounded off outwards and only | black besides the anterior margin ; secondaries 

 marked like the 9 and for the rest the blue paler. 



Underside of the wings of both sexes brownish grey, the cross vein 

 unmarked, at f a narrow grey-brown cross line can be seen, which is edged 

 on the outer side with rather greyish white. The line is continued on the 

 primaries to vein i and on the secondaries to vein 3. Then come dark brown 

 lines, which run into a large dark yellow patch, which occupies almost all the 

 space from vein 4 to the tail corner and is marked at the end of cell 2 with 

 an oblong patch, on the lobe with a smaller round black one and between with 

 a grey shiny greenish-blue scaled one. Fringe line black, edged tailwards 

 from vein 4 with white. Fringe dark grey. 



The thorax is greyisch white, the abdomen yellowish white, like the legs, 

 and these clearly ringed with dark grey on the tarsi and shins. 



According to Snellen Isaeus Hew. is a Hypolycaena which, although 

 it certainly differs somewhat from the rest of the Javanese species of this genus, 

 he does not think it necessary to make into a separate genus. He thinks that 

 in the Britomartis cleoboides (de Niceville, Journ. Boinbay Soc. of Nat. 

 Hist., IX, /. 306). Isaeus Hew. is confused with Cleoboides (Elwes, 

 Proc. Zool. Soc. of London; 1892, /. 637, //. 44,7%. 4, 5.) as the description 

 and illustration of the latter species do not correspond to Isaeus. 



I must remark in connection with this, that Snellens description of the 

 is not made from a Javan specimen, but from one from Sumatra. I shall, 

 not however, venture to express an opinion upon this question. I should only 

 consider this justified, if I had at my disposal a large amount of material from 

 different districts. A generic difference may not be based merely upon small 

 differences in colour ; in this respect not only do the individuals from different 

 districts vary but not seldom even those from the same district, without its 

 being necessary — at least from a scientific point of view — to constantly make 

 separate subspecies of them, and to submit them to a zoological baptism. 



2. Erylus Gdt. (Pi. XXVI, 158^, ^). 



GoDART, Enc. Meth., IX, /. 633, N'o. 60 (1819 — 23). Folyommatus Erylus. 

 Hewitson, ///. Diurn, Lep.,p. \<^,pl. 21, fig. i, 2, 4 (1866) Hypolycaena „ 



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